1. Field of the Invention
The present invention relates to a reverse osmosis treatment system.
2. Related Art
In s seawater desalination system, demands for energy saving of the system are more growing. As a system for meeting the demands for the energy saving, systems using a reverse osmosis membrane (i.e., RO Membrane) are known, as disclosed in the Japanese Unexamined Patent Application Publications Nos. 2014-184438 and 2013-126636. In those systems, a large volume of RO permeate is obtained from a small volume of to-be-treated water.
Further, the Japanese Unexamined Patent Application Publications No. 2014-136186 discloses an energy recovery device which recovers pressure energy from brine discharged from a reverse osmosis separation device and converts the pressure energy to energy for desalinating seawater.
Conventionally, the reverse osmosis treatment system using a reverse osmosis membrane such as the above mentioned seawater desalination system discharges permeate still having much energy. Hereby, for achieving the energy saving, it is needed to simultaneously recover energy generated at a brine side as well as at a permeate side, produced after being separated from to-be-treated water through a reversed osmosis membrane.
However, there has been no proposal how to specifically configure a system that can simultaneously and efficiently recover energy generated both at brine and permeate sides.
In view of the above circumstance, the present invention is directed to a reverse osmosis treatment system capable of simultaneously and efficiently recovering energy generated both at brine and permeate sides.